Effect of Over-Pressure on Pipeline Structural Integrity

Abstract

The effect of proof over-pressure on pipeline structural integrity using fracture mechanics parameters is analysed in the case of pipeline in Reversed Hydro Power Plant, made of High Strength Low Alloyed steel with 800 MPa tensile strength due to special design requirements. To assess its structural integrity, extensive testing of the full-scale prototype had been performed, including hydrostatic pressurizing. Since plastic strain was recorded during proof over-pressurizing, special attention is given to the fact that this is actually a mechanism for crack initiation and propagation. To investigate this effect micromechanical modelling is considered, as well as the Failure Assessment Diagramme. It is shown that over-pressuring has potential detrimental effect on pipeline safety, i.e. structural integrity.

Failure analysis and numerical simulation of slab carrying clamps

“…In both cases, analytical and numerical analyses provided a solid basis for structural integrity of pipelines and other equipment via finite element method application. This combination is widespread in other literature as well, especially in case studies involving the investigation of failure causes, damage effects and integrity assessment, for a wide variety of structures [7][8][9][10]. More often than not, even all of this is insufficient, and other methods may need to be included, such as risk analysis [11,12].…”

Risk Management of a Hydro Power Plant – Fracture Mechanics Approach

“…its most critical components, like pressure vessels for air storage. Having in mind relatively simple geometry, so-called engineering approach has been used, including the risk matrix analysis, [2][3][4] 2 HPP BAJINA BASTA -GENERAL DESCRIPTION [3,4] Reversable HPP "Bajina Bašta" operates within the HPP "Bajina Basta", Fig. 1, and represents the expansion of the existing plant, thus enhancing the energy characteristics of HPP "Bajina Basta" to the extent that they create a new modified plant with a very high flexibility, a high guaranteed power and a large amount of accumulated energy from hydroelectric power station.…”